JP2009237016A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To air-cool a toner storage part storing toner and a transfer belt to which a toner image is transferred. <P>SOLUTION: Air flowing into a housing 60 from air ports 62A and 62B flows along a guide member 68, between the top plate part 62A of a top cover 62 and toner cartridges 44M, 44C and 44K and descends along an inclined part 62B, while being guided by a guide member 69, to flow toward a belt cover 70. The air sent to the belt cover 70 passes through through-holes 72 and 73, to be blown to an intermediate transfer belt 25. Then, the air blown to the intermediate transfer belt 25 is sent to the side of image forming units 13Y, 13M, 13C and 13K via the circumference of the intermediate transfer belt 25. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that forms an image using a transfer belt.

In an image forming apparatus such as a copying machine or a printer that employs an electrophotographic system, an image is formed with toner, so it is important to maintain the toner in a good state. When the temperature exceeds a certain temperature, the toner is solidified, and the toner cannot be moved well from the developing unit to the photosensitive drum, from the photosensitive drum to the transfer belt, or from the photosensitive drum to the recording medium. There arises a problem that a toner image cannot be obtained. For this reason, conventionally, a method of suppressing the temperature rise inside the process cartridge has been devised (for example, see Patent Documents 1 to 3).
JP 2006-184436 A JP 2006-215481 A Japanese Patent Laying-Open No. 2005-10767

  An object of the present invention is to provide an image forming apparatus capable of air-cooling a toner storage section in which toner is stored and a transfer belt to which a toner image is transferred.

  The image forming apparatus of the present invention is endless and is disposed on one side of the belt surface of the transfer belt, the transfer belt transferring the toner image onto the belt surface while being circulated, and transferring the image to the belt surface And an image forming unit, a toner reservoir disposed on the opposite side of the image forming unit with the transfer belt interposed therebetween, and an outside covering the opposite side of the toner reservoir to the transfer belt. A top cover that includes an inclined portion that is inclined in a direction approaching the transfer belt on one side, and the top cover. The transfer belt, the image forming unit, and the toner storage portion are disposed inside. And a housing having an air port for allowing air to flow into the toner storage section, and the transfer belt and the toner storage section. And a through hole penetrating the transfer belt side and the toner storage portion side at least at a position corresponding to the inclined portion of the top cover. Has been.

  In the image forming apparatus of the present invention, a partition member is provided between the transfer belt and the toner reservoir. As long as the partition member is disposed between the transfer belt and the toner storage portion and covers the belt surface, the partition member may constitute a part of a belt unit including the transfer belt. It may be a partition plate that partitions the inside of the forming apparatus. A through hole is formed in the partition member, and the air that flows into the toner storage portion from the air port flows toward the transfer belt along the inclined portion of the top cover, and flows into the transfer belt through the through hole.

  According to the image forming apparatus of the first aspect, the toner storage unit and the transfer belt can be air-cooled.

  According to the image forming apparatus of the second aspect, air can be blown in the direction opposite to the circulation driving direction of the transfer belt from the through hole toward the transfer belt.

  According to the image forming apparatus of the third aspect, air can be more efficiently sent from the toner storage portion toward the through hole.

  According to the image forming apparatus of the fourth aspect, air can be effectively introduced by the blower.

  Embodiments of an image forming apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 shows an image forming apparatus 10 according to an embodiment of the present invention.

  The image forming apparatus 10 is a tandem digital color printer, and image data sent from an exposure apparatus for a manuscript (not shown) or a personal computer is sent to an image processing apparatus 12 (for example, IPS: Image Processing System). And predetermined image processing is performed. Image data that has been subjected to predetermined image processing by the image processing device 12 is also processed by the image processing device 12 into 4 of yellow (Y), magenta (M), cyan (C), and black (K) (each 8 bits). The color original reproduction color material gradation data is converted and sent to the exposure device 14. In this exposure device 14, image exposure with laser light LB is performed in accordance with document reproduction color material gradation data of a predetermined color.

  As shown in FIG. 2, the image forming apparatus 10 includes a housing 60, and the image forming unit 13 </ b> Y, 13 </ b> M, 13 </ b> C, 13 </ b> K, the transfer unit 22, and the toner cartridges 44 </ b> Y, 44 </ b> M, 44 </ b> C are provided inside the housing 60. , 44K are arranged. The image forming units 13Y, 13M, 13C, and 13K are disposed below the transfer unit 22, and the toner cartridges 44Y, 44M, 44C, and 44K are disposed above the transfer unit 22, respectively. The upper sides of the toner cartridges 44 </ b> Y, 44 </ b> M, 44 </ b> C, 44 </ b> K are covered with a top cover 62 that forms a part of the housing 60. An exposure device 14 is disposed below the image forming units 13Y, 13M, 13C, and 13K.

  The four image forming units 13Y, 13M, 13C, and 13K of yellow (Y), magenta (M), cyan (C), and black (K) are arranged in parallel at regular intervals in the horizontal direction. . These four image forming units 13Y, 13M, 13C, and 13K are all configured in the same manner. The photosensitive drums 15Y, 15M, 15C, and 15K that are driven to rotate, and the photosensitive drums 15Y, 15M, and 15C, A charging roll 16 that uniformly charges the surface of 15K, a developing device 17 that develops the electrostatic latent image formed on the photosensitive drums 15Y, 15M, 15C, and 15K with toner of a predetermined color, and a photosensitive drum And a cleaning device 18 for cleaning the surfaces of 15Y, 15M, 15C, and 15K.

  The exposure device 14 is configured in common to the four image forming units 13Y, 13M, 13C, and 13K, and modulates four semiconductor lasers (not shown) in accordance with the original reproduction color material gradation data for each color. Laser light LB-Y, LB-M, LB-C, and LB-K are emitted from the semiconductor laser in accordance with the gradation data. Of course, the exposure device 14 may be individually configured for each of a plurality of image forming units. The laser beams LB-Y, LB-M, LB-C, and LB-K emitted from the semiconductor laser are irradiated to the polygon mirror 19 through an f-θ lens (not shown), and are deflected and scanned by the polygon mirror 19. The Laser beams LB-Y, LB-M, LB-C, and LB-K deflected and scanned by the polygon mirror 19 pass through an imaging lens (not shown) and a plurality of mirrors, and the photosensitive drums 15Y, 15M, 15C, Scan exposure is performed obliquely from below at an exposure point on 15K.

  Since the exposure device 14 scans and exposes images on the photosensitive drums 15Y, 15M, 15C, and 15K from below, the exposure device 14 includes four image forming units 13Y, 13M, and 13C positioned above. The toner may fall from the 13K developing device 17 and be contaminated. Therefore, the periphery of the exposure apparatus 14 is hermetically sealed by a rectangular parallelepiped frame 20, and four laser beams LB-Y, LB-M, LB-C, and LB-K are applied to the upper portion of the frame 20. In order to expose the photosensitive drums 15Y, 15M, 15C, and 15K of the image forming units 13Y, 13M, 13C, and 13K, transparent glass windows 21Y, 21M, 21C, and 21K are provided as shield members. Yes.

  Image data of each color is sequentially output from the image processing device 12 to the exposure device 14. Laser beams LB-Y, LB-M, LB-C, and LB-K emitted from the exposure device 14 in accordance with image data are scanned and exposed on the surface of the corresponding photosensitive drums 15 to form an electrostatic latent image. Is done. The electrostatic latent images formed on the photoconductor drums 15Y, 15M, 15C, and 15K are yellow (Y), magenta (M), cyan (C), and black (black) by developing units 17Y, 17M, 17C, and 17K, respectively. K) is developed as a toner image of each color.

  A transfer unit 22 is disposed on each of the image forming units 13Y, 13M, 13C, and 13K. The transfer unit 22 includes an intermediate transfer belt 25, a belt cover 70, four primary transfer rolls 26Y, 26M, 26C, and 26K, a drive roll 27, a tension roll 24, and a backup roll 28.

  The intermediate transfer belt 25 is wound around the drive roll 27, the tension roll 24, and the backup roll 28 with a constant tension. The intermediate transfer belt 25 is rotated in the direction shown in FIG. Circulation is driven at a predetermined speed in the clockwise X direction.

  The photosensitive drums 15Y, 15M, 15C, and 15K are disposed so as to contact the lower belt outer surface of the intermediate transfer belt 25 that is driven to circulate in FIG. 1, and primary transfer rolls 26Y, 26M, and 26C disposed on the inner surface of the belt. , 26K, the intermediate transfer belt 25 is sandwiched.

  The yellow (Y), magenta (M), cyan (C), and black (K) toner images sequentially formed on the photosensitive drums 15Y, 15M, 15C, and 15K are primary transfer rolls 26Y, 26M, and 26C. , 26K, and multiple transfer onto the intermediate transfer belt 25. A transfer bias power source (not shown) is connected to the primary transfer rolls 26Y, 26M, 26C, and 26K, and a transfer bias having a polarity opposite to a predetermined toner polarity (positive polarity in the present embodiment) is set at a predetermined timing. Applied.

  The yellow (Y), magenta (M), cyan (C), and black (K) toner images transferred onto the intermediate transfer belt 25 in a multiple manner are transferred to the backup roll 28 by a secondary transfer roll 29. The sheet P that has been secondarily transferred onto the sheet P and onto which the toner images of these colors have been transferred is conveyed to the fixing device 31 positioned above. The secondary transfer roll 29 is in pressure contact with the side of the backup roll 28 and is configured to secondary-transfer toner images of each color onto the sheet P conveyed from below to above. The fixing device 31 includes a heating roll 56 heated to a predetermined temperature, and a pressure roll 58 pressed against the heating roll 56. The sheet P on which the toner image of each color has been transferred is subjected to a fixing process by heat and pressure at the pressure contact portion between the heating roll 56 and the pressure roll 58 and then provided on the upper portion of the image forming apparatus 1 by the discharge roll 32. It is discharged onto the discharged discharge tray 33.

  A sheet P having a predetermined size from the sheet feeding cassette 34 is once conveyed to a registration roll 38 via a sheet conveying path 37 by a sheet feeding roller 35 and a pair of rollers 36 for separating and conveying the sheet, and stopped. The sheet conveyance path 37 of the fed sheet P is directed upward in the vertical direction. The sheet P supplied from the paper feed cassette 34 is sent to the secondary transfer position of the intermediate transfer belt 25 by a registration roll 38 that rotates at a predetermined timing.

  Air ports 64 and 66 are formed on the upper back side of the housing 60. The air port 64 is configured on the upper surface of the housing 60, and the air port 66 is configured on the side surface of the housing 60. The air ports 64 and 66 are opening holes that allow the outside and the inside of the housing 60 to communicate with each other, and external air flows into the toner cartridges 44Y, 44M, 44C, and 44K in the housing 60 through the air ports 64 and 66. The

 A blower 50 is provided in the vicinity of the air ports 64 and 66. The blower 50 promotes the inflow of air from the air ports 64 and 66 and sends air toward the toner cartridges 44Y, 44M, 44C, and 44K. A blower 51 is also provided in the vicinity of the fixing device 31, and air in the housing 60 is discharged from the air port 61.

  The top cover 62 constitutes an upper surface portion of the housing 60 and includes an upper plate portion 62A disposed on the upper side of the toner cartridges 44Y, 44M, 44C, 44K, and one side of the upper plate portion 62A (on the toner cartridge 44K side). ) To the transfer unit 22 and has an inclined portion 62B that forms an inclined surface. The upper plate portion 62A and the inclined portion 62B constitute a part of the outer shape of the image forming apparatus 10 and also serve as a discharge tray for receiving the sheet P that has been image-formed and discharged. Guide members 68 and 69 are formed on the lower surface side of the top cover 62. As shown in FIG. 3, the guide member 68 is arranged so that the air flowing in from the air port 62A flows along the longitudinal direction of the toner cartridges 44M, 44C, 44K. The guide member 69 is disposed in a direction orthogonal to the longitudinal direction of the toner cartridges 44M, 44C, 44K, and is disposed from the upper plate portion 62A to the vicinity of the end portion of the inclined portion 62B.

  The toner cartridges 44Y, 44M, 44C, and 44K store toners of yellow (Y), magenta (M), cyan (C), and black (K), respectively. Toner is supplied from the toner cartridges 44Y, 44M, 44C, 44K to the developing devices 17 of the image forming units 13Y, 13M, 13C, 13K.

  A belt cover 70 is disposed between the toner cartridges 44Y, 44M, 44C, and 44K and the intermediate transfer belt 25. As shown in FIG. 4, the belt cover 70 has a plate shape that covers the upper surface of the intermediate transfer belt 25, and is provided to prevent the user from directly touching the intermediate transfer belt 25. Through holes 72 and 73 are formed in the belt cover 70. The through holes 72 and 73 are configured at least at a position corresponding to the inclined portion 62B, that is, at a position facing the inclined portion 62B, and are configured by a plurality of holes. The through hole that penetrates the belt cover 70 may be formed on the entire surface of the belt cover 70. As shown in FIG. 5, the through hole 72 is inclined at an angle θ from the toner cartridge 44 side toward the intermediate transfer belt 25 side so as to go in the direction opposite to the circulation drive direction X of the intermediate transfer belt 25. Due to this inclination, the air flowing in from the toner cartridge side is sent in the direction opposite to the circulation drive direction X of the intermediate transfer belt 25 and is applied to the intermediate transfer belt 25, so that the relative speed at which air is blown onto the belt surface is increased. As a result, the air cooling effect of the intermediate transfer belt 25 can be improved.

  FIG. 6 shows an air flow in the housing 60 of the image forming apparatus 10 having the above configuration. The arrows in the figure are the path and direction of air flow. The air flowing into the housing 60 from the air ports 62A and 62B flows along the guide member 68 between the upper plate portion 62A of the top cover 62 and the toner cartridges 44M, 44C, and 44K, and also flows into the guide member 69. While being guided, the vehicle descends along the inclined portion 62 </ b> B and flows toward the belt cover 70. Further, part of the air flowing into the housing 60 from the air ports 62A and 62B flows toward the belt cover 70 through the gaps formed between the toner cartridges 44Y, 44M, 44C and 44K. The air sent to the belt cover 70 is blown to the intermediate transfer belt 25 through the through holes 72 and 73. The air blown to the intermediate transfer belt 25 is then sent to the image forming units 13Y, 13M, 13C, and 13K via the outer periphery of the intermediate transfer belt 25, and adjacent image forming units 13Y, 13M, 13C, It is sent to the exposure apparatus 14 from between 13K.

  A part of the air that flows downward along the inclined portion 62 </ b> B while being guided by the guide member 69 is discharged from the air port 61 to the outside via the vicinity of the fixing device 31.

  As described above, the air that has flowed into the housing 60 from the air ports 62A and 62B passes through the toner cartridges 44Y, 44M, 44C, and 44K, the intermediate transfer belt 25, the image forming units 13Y, 13M, and the like. 13C, 13K and the exposure apparatus 14 are distributed. Thereby, solidification and fusion of the developer due to heat can be suppressed.

  In the present embodiment, the example in which the belt cover 70 that is a member constituting a part of the transfer unit 22 is used as the partition member has been described, but the partition member may be configured by a part of the housing. Alternatively, other members may be used.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. 1 is a perspective view illustrating a schematic internal configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a diagram illustrating a schematic internal configuration of an image forming apparatus according to an embodiment of the present invention as viewed from above. It is a perspective view of the belt cover of the embodiment of the present invention. It is a partial sectional view of a belt cover of an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating air flow in the image forming apparatus according to the exemplary embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 13Y, 13M, 13C, 13K Image forming unit 14 Exposure apparatus 22 Transfer unit 25 Intermediate transfer belt 44Y, 44M, 44C, 44K Toner cartridge 50 Blower 60 Case 61 Air port 62 Top cover 62A Air port 62B Inclined part 62A Upper plate portion 64 Air port 66 Air port 68 Guide member 69 Guide member 70 Belt cover 72 Through hole 73 Through hole P Sheet X Circulation drive direction

Claims (4)

A transfer belt which is endless and is circulated and has a toner image transferred to the belt surface;
An image forming unit disposed on one side of the belt surface of the transfer belt and transferring an image to the belt surface;
A toner reservoir disposed on the opposite side of the image forming unit across the transfer belt;
A top cover that covers the opposite side of the toner storage portion from the transfer belt and defines an inclined portion that is inclined in a direction approaching the transfer belt on one side;
A housing configured to include the top cover, the transfer belt, the image forming unit, and the toner storage unit disposed therein, and configured to have an air inlet that allows air to flow into the toner storage unit;
A partition member that is disposed between the transfer belt and the toner storage portion and partitions the transfer belt and the toner storage portion;
With
The image forming apparatus, wherein the partition member includes a through-hole penetrating the transfer belt side and the toner storing portion side at a position corresponding to the inclined portion of the top cover.   2. The image according to claim 1, wherein the through hole is inclined from the toner storage unit side toward the transfer belt side in a direction opposite to a circulation drive direction of the transfer belt. Forming equipment.   3. The guide member according to claim 1, further comprising a guide member that is formed on the top cover and guides the air flowing in from the air port toward the through hole from the toner storage portion. Image forming apparatus.   The image forming apparatus according to claim 1, further comprising a blower that allows air to flow from the air port to the toner storage unit.

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